Isotopes of selenium

Use of radioisotopes

The isotope selenium-75 has radiopharmaceutical uses. For example, it is used in high-dose-rate endorectal brachytherapy, as an alternative to iridium-192.

In paleobiogeochemistry, the ratio in amount of selenium-82 to selenium-76 (i.e, the value of δ^82/76Se) can be used to track down the redox conditions on Earth during the Neoproterozoic era in order to gain a deeper understanding of the rapid oxygenation that trigger the emergence of complex organisms.